I know we got to this a bit late, but better late than never...
After the drive crashed, did you put a known working drive in slot 1 to test? From the context of the post it doesn't sound like it. Only after you replace the drive will you be able to boil down what part it is. In order to logically break down the problem you need to start with a constant. Best approach is to get a working drive (tested in another machine), then replace the drive if it continues to fail. Next step: look for HD and RAID drivers. If that fails, replace the RAID controller with a known working controller and continue this process of part elimination until it is fixed. Then at whatever part down the line it was fixed, replace everything but that part and work your way back to the beginning. It’s the only way to be sure of to catch the real issue at hand.
